Several pieces are broken for screw holes. I tried using this though it is for metal this time. Although I opened more than 100 pilot holes, it used to break one or two drills before, but as expected it never broke. I felt that it is a consumable item but it can be used

It is used for drilling holes of M4 tap. Excellent sharpness It is very useful. The difficulty is that twisting is different from Japanese products to sharpen the drill, so it takes time and effort to reuse it.

I was worried because it was a Korean manufacturer, but I feel that I used it because the core does not shake well and it breaks well and it does not break easily. Depending on the lot, there is some variation in sharpness, but it is divisible within the error level. Considering the price, we judge it better than the domestic manufacturer.